CIE IGCSE Biology: 復(fù)習(xí)筆記：20.1.1 Ensuring Food Supply Intensive Food Production Making food production more?intensive?means producing food more?efficiently?with a finite amount of land an...
CIE IGCSE Biology: 復(fù)習(xí)筆記：19.1.6 Populations Definition of Population A population is defined as a group of organisms of one species, living in the same area at the same time Other important def...
CIE IGCSE Biology: 復(fù)習(xí)筆記：19.1.5 Nutrient Cycles The Carbon Cycle Nutrients such as carbon and nitrogen are not endless resources There is a finite amount of each element on the planet an...
CIE IGCSE Biology: 復(fù)習(xí)筆記：19.1.4 Pyramids of Energy: Extended Pyramids of Energy: Extended In order for the energy to be passed on,?it has to be consumed (eaten) However?not all of the en...
CIE IGCSE Biology: 復(fù)習(xí)筆記：19.1.3 Pyramids of Number & Biomass Pyramids of Number A pyramid of numbers shows?how many organisms?we are talking about at each level of a food chain. The?...
CIE IGCSE Biology: 復(fù)習(xí)筆記：19.1.2 Food Chains & Food Webs Food Chains & Food Webs A food chain with three trophic levels A food chain shows the transfer of energy from one o...
CIE IGCSE Biology: 復(fù)習(xí)筆記：19.1.1 Transfer of Energy Transfer of Energy Transfer of Energy The Sun is the principal source of energy input to biological systems Energy flows through living organi...
CIE IGCSE Biology: 復(fù)習(xí)筆記：18.1.5 Artificial Selection Selective Breeding Selective breeding means to?select individuals with desirable characteristics and breed them together The p...
CIE IGCSE Biology: 復(fù)習(xí)筆記：18.1.4 Natural Selection Natural Selection In any environment, the individuals that have the best adaptive features are the ones most likely to survive and repro...
